28/09/2025
Hot off the press 🔥
The Broken Wing Sign🦅: A New Clinical Test to Detect Gluteus Medius Pathology with and without Fatty Infiltration
🦵 Gluteus medius pathology, including tendon tears and fatty degeneration, is a major cause of lateral hip pain, limp, and functional impairment (Kenanidis et al., 2020; Pianka et al., 2021). These lesions are common in patients with hip osteoarthritis and after total hip arthroplasty (THA) and can significantly impact surgical outcomes (Whiteside & Roy, 2019; Howell et al., 2001; Bunker et al., 1997). While magnetic resonance imaging (MRI) remains the gold standard for evaluating tendon integrity and fatty infiltration (Bogunovic et al., 2015; Engelken et al., 2014), it is not always readily available preoperatively. Clinical tests such as the Trendelenburg sign and resisted abduction are widely used, but they suffer from limited sensitivity and practical constraints (Bird et al., 2001; Ortiz-Declet et al., 2019). Therefore, novel physical examination maneuvers that correlate with MRI and intraoperative findings are needed for early and accurate detection of hip abductor insufficiency.
📘 Sierra et al. (2025, https://pubmed.ncbi.nlm.nih.gov/40938961/) introduced the “broken wing sign”, a new clinical test designed to detect gluteus medius tears and muscle atrophy. In a prospective study of 59 patients (75 hips; mean age 69.5 years), the maneuver was performed in a prone position with the knee flexed at 90°, requiring active hip extension (figure below). A positive sign was defined as ≥10° of compensatory external rotation, with ≥30° considered “highly positive.”
🩻 MRI and intraoperative findings served as reference standards.
✅ The test demonstrated strong diagnostic performance, with 81.8% sensitivity, 80.0% specificity, and a diagnostic odds ratio of 17.8 for detecting any tear.
✅ For massive tears, the negative predictive value reached 96.1%.
✅A ≥30° threshold yielded 100% specificity and positive predictive value for tendon tears.
✅The degree of external rotation correlated with fatty infiltration severity, showing 88% sensitivity for Goutallier grade ≥3 and 100% sensitivity for grade 4.
💡 Compared to the Trendelenburg sign, which was often unfeasible due to pain or poor balance, the broken wing sign was easier to perform and maintained comparable diagnostic accuracy. The authors conclude that this maneuver provides a reliable, accessible, and clinically valuable tool to guide MRI utilization, preoperative planning, and management of abductor pathology.
📸 Fig. 1-A The patient is positioned prone on the examination table with the right knee flexed to 90°. While actively extending the right hip, the leg is lifted straight upward, maintaining the thigh in neutral rotation. No excessive internal or external rotation is observed, indicating a negative broken wing sign (normal finding).
📸 Fig. 1-B In the same position, weakness of the contralateral gluteus medius allows the hip to drift into external rotation, causing the foot to move inward toward the midline. This compensatory motion indicates a positive broken wing sign.
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📚 References
• Bird, P. A., Oakley, S. P., Shnier, R., & Kirkham, B. W. (2001). Prospective evaluation of magnetic resonance imaging and physical examination findings in patients with greater trochanteric pain syndrome. Arthritis & Rheumatism, 44(9), 2138–2145.
• Bogunovic, L., Lee, S. X., Haro, M. S., Frank, J. M., Mather, R. C. III, Bush-Joseph, C. A., & Nho, S. J. (2015). Application of the Goutallier/Fuchs rotator cuff classification to the evaluation of hip abductor tendon tears and clinical correlation with outcome after repair. Arthroscopy, 31(11), 2145–2151.
• Bunker, T. D., Esler, C. N., & Leach, W. J. (1997). Rotator-cuff tear of the hip. Journal of Bone and Joint Surgery (Br), 79(4), 618–620.
• Engelken, F., Wassilew, G. I., Köhlitz, T., Brockhaus, S., Hamm, B., Perka, C., & Diederichs, G. (2014). Assessment of fatty degeneration of the gluteal muscles in patients with THA using MRI. Journal of Arthroplasty, 29(1), 149–153.
• Howell, G. E., Biggs, R. E., & Bourne, R. B. (2001). Prevalence of abductor mechanism tears of the hips in patients with osteoarthritis. Journal of Arthroplasty, 16(1), 121–123.
• Kenanidis, E., Kyriakopoulos, G., Kaila, R., & Christofilopoulos, P. (2020). Lesions of the abductors in the hip. EFORT Open Reviews, 5(8), 464–476.
• Ortiz-Declet, V., Chen, A. W., Maldonado, D. R., Yuen, L. C., Mu, B., & Domb, B. G. (2019). Diagnostic accuracy of a new clinical test (resisted internal rotation) for detection of gluteus medius tears. Journal of Hip Preservation Surgery, 6(4), 398–405.
• Pianka, M. A., Serino, J., DeFroda, S. F., & Bodendorfer, B. M. (2021). Greater trochanteric pain syndrome: Evaluation and management of a wide spectrum of pathology. SAGE Open Medicine, 9, 20503121211022582.
• Sierra, R. J., Guarin Perez, S. F., Restrepo, D. J., Howe, B. M., & Tai, T.-W. (2025). The broken wing sign: A new clinical test to detect gluteus medius pathology with and without fatty infiltration. Journal of Bone and Joint Surgery (Am), 00, 1–6. https://doi.org/10.2106/JBJS.25.00427
• Whiteside, L. A., & Roy, M. E. (2019). Incidence and treatment of abductor deficiency during total hip arthroplasty using the posterior approach. Bone & Joint Journal, 101-B(6_Supple_B), 116–122.
